One of the most beautiful and powerful features of WordPress is its flexibility and extensibility – everybody can make WordPress to fit their needs.

But with great power comes great responsibility of doing things the right way. Any WordPress developer can tell endless horror stories of sites they took over from somebody else – modified Core, modified plugins, thousands of lines of code in functions.php, etc.

This talk introduces the main ways of extending WordPress and explain how to use them properly, with particular emphasis on WordPress hook system.